You're not going to find a new laptop with dedicated graphics at $400. Maybe a used one from Ebay or Craigslist. I recently got my girl a laptop with a 4250, it averages Sims3 1366x768 at about 30fps even with AA turned up a little, some settings on low, some high. She is happy with it.
Whats the processor in that one you bought and what was the price?